The underage Rosemarie is still too young to run her inherited farm by herself; but she's more than aware that her foster father and the farm's administrator, the farmer Schlieker, is constantly skimming from the farm's finances to line his own pocket.
Three mice run, cavort, sing and dance around in the stores and restaurants a big city at night. They wind up in a café for an early-morning snack and stocking up on food provisions before they return to the safety of their den beneath a man-hole cover in the street.
Herr Werther, a new magistrate to the Grand Duchy of Walheim who is a violinist and poet, seems to have fate on his side as he meets and pursues a beautiful local woman, Charlotte.
This film was mainly shot in the Japanese skiing resort Hokkaido in 1937-38 and was intended to create support for the coming winter olympics of 1940 in Japan which however were cancelled because of the Japanese-Chinese war.
In the village of Sableuse, the local manor has been bought out by a nouveau riche, Emile Cousinet. When his wife Lisette, a former music hall actress, flees to Paris with young Pierre de Sableuse, Cousinet asks Father Pellegrin, the village vicar, to bring the lost sheep back home.